ScopeFIR designs FIR filters using several different filter design methods. Since the design parameters of each method is different, ScopeFIR provides one or more Specification Editors for each method.

The Specification Editor appears in the upper left corner of a four-pane window, and can be any of the following following Design Types:

• Simple Parks-McClellan
• Advanced Parks-McClellan
• Windowed Sinc
• Raised Cosine
• Lth-Band (Nyquist)
• Import/Boxcar
• CIC
• Maximally Flat

The other three windows are blank until you design a filter. After you design a filter, the upper right pane shows you the filter's coefficients, the lower left pane shows the filter's Frequency Response plot, and the lower right pane shows the filter's Impulse Response plot. (For a FIR filter the Impulse Response is the same as the coefficients, so this is really just a plot of the coefficients.)

When you click on one of the four panes, it flashes momentarily to show you that it has the input focus. The menu changes accordingly: the Coefficient Editor, Frequency Response Plot, and Impulse Response plot enable the Coefficent, Frequency and Impulse menus, respectively. Therefore, if you need a menu is not shown, simply click on the corresponding pane to bring it back again.

You can adjust the relative sizes of the four windows using the mouse. Adjust the size of the top two panes relative to the bottom two by clicking and dragging on the horizontal divider line in the center. Adjust the size of the left and right panes by clicking and dragging the vertical divider between the left and right panes.

The plots in the four-pane editor window are useful for doing the initial design, but sometimes you will want larger, separate windows to show the coefficients, the Frequency Response, or the Impulse Response. Commands under the View menu allow you to do just that. Each View command creates a new window.

You can also create these separate Frequency and Impulse plots using the buttons on the toolbar that look like like miniature plots. However, there is one important difference between the toolbar buttons and the View menu: when you use the View menu, a new view is added each time. But when you use the toolbar, a view is added only the first time; the second time you hit the View button, ScopeFIR simply brings the existing view to the top. This is a very convenient way to switch among the editor view, the coefficient view, the Frequency Response view, and the Impulse Response view. By using these buttons effectively, you can quickly examine all aspects of your filter design.